Infections in Child Day Care Centers and Later Development of Asthma, Allergic Rhinitis, and Atopic Dermatitis Infections in Child Day Care Centers: Prospective Follow-up Survey 12 Years After Controlled Randomized Hygiene Intervention
Dunder T, Tapiainen T, Pokka T, Uhari M. Arch Pediatr Adolesc Med. 2007;161(10):972–977
PURPOSE OF THE STUDY. To evaluate the effect of prevention of common infections in child day care centers (CDCCs) on the later development of allergic disease.
STUDY POPULATION. Children <2 years of age were recruited from 20 CDCCs in Finland for a 15-month randomized, controlled hygiene intervention trial conducted in 1991–1992. Among the children in the intervention CDCCs, there were 27% fewer episodes of acute otitis media and 24% fewer days of antimicrobial agents.
METHODS. Questionnaires were sent in 2003 (12 years later) to 1376 participants of the previous intervention trial; 928 participated (response rate: 68%). The main outcome measures were the number of respondents with a physician diagnosis of asthma, allergic rhinitis, and/or atopic dermatitis (AD) and those who reported symptoms of atopic disease.
RESULTS. No differences were found between the intervention and control groups with regard to rates of asthma, allergic rhinitis, or AD or with frequency of atopic symptoms.
CONCLUSIONS. The prevention of common respiratory tract and enteric infections during early childhood does not change later allergic morbidity.
REVIEWER COMMENTS. This particular hygiene intervention, aimed at decreasing the frequency of common childhood upper respiratory and gastrointestinal illnesses, was not successful in decreasing the development of asthma, allergic rhinitis, or AD among this cohort. The authors argued that the magnitude of the reduction in infections and duration of the intervention should have led to an increase in asthma rates as proposed by the hygiene hypothesis. However, the infection history was based on clinical symptoms and use of antibiotics rather than more definitive laboratory diagnostic measures for specific bacteria and/or viruses. In addition, the follow-up data were based solely on questionnaire findings, which have an inherent reporting bias. Regardless, additional studies are necessary to characterize the role of the hygiene hypothesis in the development of atopic disease.
- Copyright © 2008 by the American Academy of Pediatrics